I do think, that the "Bernburger Jäger" is the Gruppenemblem (later carried on by I./ZG 2) and the "Hand" is the Staffelemblem. There's a photo in "Die deutsche Tagjagd" on one of the first pages which shows Bf 109 D of "Jagdgruppe Bernburg" (aka I./JG 137) during war games. In the front there are several Bf 109 Ds of 1./JG 137 completely devoid of any emblems. But in the background the Bf 109s of 2./JG 137 can be seen and they carry the "Bernburger Jäger" beneath the cockpit windshield.